This website runs in a virtual machine under vmware server. It is clustered between two servers using heartbeat and DRBD.
When VMware server starts up a virtual machine it generates a uuid (unique id) based on the machine it is running on and stores this in the .vmx file.
When heartbeat switches from slave to master, it will start VMware server (which is setup as a resource in the haresources file).
Virtual machines that you want started automatically when you start VMware server will not start because the uuid changes between the master and backup systems. To get around this problem always do the following:
- edit the .vmx file and add the following line
uuid.action = "keep"
If this is not done then everytime you try to run the virtual machine on the backup system in your cluster, VMware server will complain that the virtual machine has been copied or moved and it will not start it.
- set the virtual machine to power off when vmware is stopped. Do not set this to "suspend" or it will not restart on the backup machine.
This will allow the virtual machine to start properly on the backup machine.
TIP
If you are using the Oracle Gateway in Recital, make sure the Oracle environment (ORACLE_HOME, ORACLE_SID etc.) is set up before starting the Recital Server. If not, you will see the error ORA-01019. A call to the Oracle environment setup script can be added to the /etc/init.d/recital script if your Recital Server is set to run on startup.
If you are using the Oracle Gateway in Recital, make sure the Oracle environment (ORACLE_HOME, ORACLE_SID etc.) is set up before starting the Recital Server. If not, you will see the error ORA-01019. A call to the Oracle environment setup script can be added to the /etc/init.d/recital script if your Recital Server is set to run on startup.
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After an extended period of intense software development, we are pleased to announce the release of Recital 10 which is a milestone in our development efforts.
Recital 10 is comprised of major new versions of all of our products (which are all now Cluster Ready) as well as some new products, and a collection of open source technologies fully supported by ourselves to our customer base.
The Recital 10 release notes can be found here.
The Recital 10 release notes can be found here.
- Recital
A powerful scripting language with an embedded database used for developing desktop database applications on Linux and Unix.
- Recital Server
A cross-platform SQL database and application server.
- Recital Web
A server-side scripting language with an embedded SQL database for creating web 2.0 web applications.
The PHP ODBC functions can be used to access Recital data via the Recital Universal ODBC Driver.
The following example connects to a Recital ODBC datasource, executes a query then outputs all the results from the resultset.
<?php
$sql = "select country from customers limit 10";
$conn = odbc_connect('Recital ODBC test', '?', '?');
$rs = odbc_exec($conn, $sql);
odbc_result_all($rs);
odbc_close($conn);
?>
Output:
<table><tr><th>Country</th></tr>
<tr><td>Germany </td></tr>
<tr><td>Mexico </td></tr>
<tr><td>Mexico </td></tr>
<tr><td>UK </td></tr>
<tr><td>Sweden </td></tr>
<tr><td>Germany </td></tr>
<tr><td>France </td></tr>
<tr><td>Spain </td></tr>
<tr><td>France </td></tr>
<tr><td>Canada </td></tr>
</table>
For information on installing and configuring the Recital Universal ODBC Driver and creating and modifying datasources, please see the Documentation section of this web site.
Note: Use of ? for the username and password on the local server is dependent on DB_LOCAL_LOGIN being enabled.
The following example connects to a Recital ODBC datasource, executes a query then outputs all the results from the resultset.
<?php
$sql = "select country from customers limit 10";
$conn = odbc_connect('Recital ODBC test', '?', '?');
$rs = odbc_exec($conn, $sql);
odbc_result_all($rs);
odbc_close($conn);
?>
Output:
<table><tr><th>Country</th></tr>
<tr><td>Germany </td></tr>
<tr><td>Mexico </td></tr>
<tr><td>Mexico </td></tr>
<tr><td>UK </td></tr>
<tr><td>Sweden </td></tr>
<tr><td>Germany </td></tr>
<tr><td>France </td></tr>
<tr><td>Spain </td></tr>
<tr><td>France </td></tr>
<tr><td>Canada </td></tr>
</table>
For information on installing and configuring the Recital Universal ODBC Driver and creating and modifying datasources, please see the Documentation section of this web site.
Note: Use of ? for the username and password on the local server is dependent on DB_LOCAL_LOGIN being enabled.
Recital is a rich and versatile product with many ways to do the same thing. Developers usually write code in the way that they are accustomed to without paying much attention to how this will perform in a multi-user environment with large amounts of users and transactions. The best way to optimize Recital applications is to use the built-in tuning capabilities introduced in Recital 10.
A good article describing the configuration of samba for file/record locking can be found here.
You can further tune samba by following this guide.
Basically you must add these directives to the smb.conf file:
[data] oplocks = False level2 oplocks = False
The default oplock type is Level1. Level2 oplocks are enabled on a per-share basis in the smb.conf file. Alternately, you could disable oplocks on a per-file basis within the share:
veto oplock files = /*.dbf/*.DBF/*.ndx/*.NDX/*.dbx/*.DBX/*.dbt/*.DBT/
You can further tune samba by following this guide.
If you specify the Common Internet File System (CIFS) when you mount the samba share then you must specify the following options
mount -t cifs {mount-point} -o username=name,pass=pass,directio
The directio option is used to not do inode data caching on files opened on this mount. This precludes mmaping files on this mount. In some cases with fast networks and little or no caching benefits on the client (e.g. when the application is doing large sequential reads bigger than page size without rereading the same data) this can provide better performance than the default behavior which caches reads (readahead) and writes (writebehind) through the local Linux client pagecache if oplock (caching token) is granted and held. Note that direct allows write operations larger than page size to be sent to the server.
If you get the following error when trying to mount the {mount-point}
Apr 22 16:57:39 bailey kernel: Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE Apr 22 16:57:39 bailey kernel: CIFS VFS: Send error in SessSetup = -13 Apr 22 16:57:39 bailey kernel: CIFS VFS: cifs_mount failed w/return code = -13The you need to create the Samba user specified on the mount command
smbpasswd -a usernameFYI - Make sure you umount all the Samba {mount-point(s)} before shutting down Samba.
TIP
The Recital Oracle Gateway requires the Oracle libclntsh.so shared library. If this file is unknown to ld.so.conf, add it using the ldconfig command.
The Recital Oracle Gateway requires the Oracle libclntsh.so shared library. If this file is unknown to ld.so.conf, add it using the ldconfig command.
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After split brain has been detected, one node will always have the resource in a StandAlone connection state. The other might either also be in the StandAlone state (if both nodes detected the split brain simultaneously), or in WFConnection (if the peer tore down the connection before the other node had a chance to detect split brain).
At this point, unless you configured DRBD to automatically recover from split brain, you must manually intervene by selecting one node whose modifications will be discarded (this node is referred to as the split brain victim). This intervention is made with the following commands:
# drbdadm secondary resource
# drbdadm disconnect resource
# drbdadm -- --discard-my-data connect resource
On the other node (the split brain survivor), if its connection state is also StandAlone, you would enter:
# drbdadm connect resource
You may omit this step if the node is already in the WFConnection state; it will then reconnect automatically.
If all else fails and the machines are still in a split-brain condition then on the secondary (backup) machine issue:
drbdadm invalidate resource